In semiconductor manufacturing processes, inspection process is directly related to reliability of a product and is very important. A semiconductor requires inspections after completion of packaging as well as steps before the packaging.
In order to inspect electric characteristics of the semiconductor before or after the packaging, an electric power is applied to a pad of the semiconductor. Applying the electric power to the pad of the semiconductor having a highly integrated circuit is nearly impossible, so that a pad having anisotropic characteristics is interposed between the semiconductor and a test stage. The electric power applied to the test stage passes through the anisotropic pad to be applied to the semiconductor, thereby performing test.
In a conventional anisotropic pad, an insulating silicon rubber is interposed between electrodes and silicon resin in which conductive particles are uniformly scattered is solidified in the electrodes, so that the electrodes form a structure in an electrically conductive state.
In the above-structure, scattering state in each of the electrodes is different so that reliability of the product is not uniform through the products, and when the electrode is pressed more than or equal to 30%, the conductive particles tear the silicon to be drifted, and thus, deterioration of product quality and decrease of lifetime may be caused.
Also, when a height of the silicon is increased, the quality is greatly decreased. In contrast, when a pitch of the electrode is decreased, the lifetime of the product is decreased and electric characteristics is deteriorated.
As another technology of anisotropic pad, a technology of implanting a wire in a silicon rubber has been studied. However, when the sire is implanted into the wire, during repeating of the test, the wire and the pad are buried in the rubber.